Methods for the controlled synthesis of layered lithium and sodium transition metal oxides using electrochemically assisted ion-exchange

Patent metadata

Field	Value
Publication number	US-2023282800-A1
Application number	US-202318176857-A
Country	US
Kind code	A1
Filing date	Mar 1, 2023
Priority date	Mar 2, 2022
Publication date	Sep 7, 2023
Grant date	—

Abstract

Methods for synthesizing layered lithium transition metal oxides from layered sodium transition metal oxides are provided. Also provided are electrodes for lithium-ion batteries that include the layered lithium transition metal oxides. Similarly, methods for the synthesis of layered sodium transition metal oxides from layered lithium transition metal oxides and electrodes for sodium-ion batteries that include the layered sodium transition metal oxides are provided. The methods couple electrochemical intercalation of alkali ions (Li+ or Na+) with ion-exchange to overcome the kinetic limitation of ion-exchange in the layered alkali transition metal oxides at low vacancy concentrations.

First claim

What is claimed is:

1 . A method for synthesizing a layered oxide having the formula Li x Na y MO 2 , where 0<x<1 and 0<y<1 and M is Co, Mn, or Ni, the method comprising:
(a) providing a layered cobalt metal oxide having the formula Na y MO 2 , where 0.57≤y≤0.67; (b) conducting a first cation-exchange on the Na y MO 2 , where 0.57≤y≤0.67, in a solution containing dissolved lithium ions to convert the Na y MO 2 , where 0.57≤y≤0.67, into a material comprising discrete phases of Li 0.94 MO 2 and Na y MO 2 , where 0.45<y<0.51; (c) conducting an electrochemical intercalation of lithium ions into the material to increase the Li 0.94 MO 2 fraction in the material and regenerate Na y MO 2 , where 0.57≤y≤0.67; and (d) conducting an additional cation-exchange on the material in the solution containing dissolved lithium ions material to increase the Li 0.94 MO 2 fraction in the material and convert the Na y MO 2 , where 0.57≤y≤0.67, back into Na y MO 2 , where 0.45<y<0.51.

2 . The method of claim 1 , further comprising repeating steps (c) and (d) two or more times.

3 . The method of claim 2 , comprising repeating steps (c) and (d) until the Li 0.94 MO 2 fraction in the material is at least 90 mol %.

4 . The method of claim 1 , wherein the solution containing dissolved lithium ions comprises a mixture of dissolved lithium ions and dissolved sodium ions and the dissolved sodium ions are present in excess.

5 . The method of claim 1 , wherein the solution containing dissolved lithium ions has a lithium ion concentration of 1 mM or lower.

6 . The method of claim 1 , wherein the solution containing dissolved lithium ions has a lithium ion concentration 0.2 mM or lower.

7 . The method of claim 1 , wherein M is Co.

8 . The method of claim 1 , wherein M is Mn.

9 . The method of claim 1 , wherein M is Ni.

10 . An electrode comprising a material comprising discrete Li 0.94 MO 2 and Na y MO 2 phases, where 0.45<y<0.51, wherein the phase fraction of Li 0.94 MO 2 in the material is at least 90 mol. %.

11 . The electrode of claim 10 , wherein the discrete Li 0.94 MO 2 and Na y MO 2 phases are disposed on an electrically conductive substrate.

12 . A method for synthesizing a layered oxide having the structure Na y MO 2 , where 0.45<y<0.51 and M is Co, Mn, or Ni, the method comprising:
providing a layered cobalt metal oxide having the structure LiMO 2 ; conducting an electrochemical deintercalation of lithium ions from the material to convert the LiMO 2 into Li 0.4 MO 2 ; and conducting a cation-exchange on the Li 0.4 MO 2 in a solution containing dissolved sodium ions to convert the Li 0.4 MO 2 into a material comprising Na y MO 2 phases, where 0.45<y<0.51, wherein the phase fraction of Na y MO 2 in the material is at least 0.98 mol. %.

13 . The method of claim 12 , wherein M is Co.

14 . The method of claim 12 , wherein M is Mn.

15 . The method of claim 12 , wherein M is Ni.

16 . An electrode comprising a material comprising Na y MO 2 phases, where 0.45<y<0.51, wherein the phase fraction of Na y MO 2 in the material is at least 0.98 mol. %.

17 . The electrode of claim 16 , wherein the Na y MO 2 phases are disposed on an electrically conductive substrate.

Assignees

• Univ Chicago

Inventors

• Liu Chong
• Han Yu

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/0525 Primary

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/0459 Primary

  Electrochemical doping, intercalation, occlusion or alloying · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title